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Living building material can be 3D printed under simulated Martian conditions at 30\u00b0C and 0.01 atm (left). A microscopic view reveals the materials porous structure with polymers and engineered yeast highlighted in yellow (right). (Ning Liu via SWNS)<\/p>\n
By Talker<\/p>\n
By Stephen Beech<\/p>\n
Scientists plan to 3D print houses on Mars<\/a> \u2014 after being inspired by freeze-dried fruit.<\/p>\n They have cooked up a recipe that they say could one day be used to construct buildings on the red planet<\/a>.<\/p>\n Mars is a hostile environment to build a house as it\u2019s bitterly cold, blasted by radiation<\/a> and a near vacuum, while traditional building materials would take months to transport from Earth.<\/p>\n Now scientists in Hong Kong have created a recipe that combines Martian rocks with Earthly ingredients: gelatin and yeast.<\/p>\n Once dried and hardened, they say the living building material is as strong as low-grade concrete and can be broken down, recycled and even brewed again for new construction.<\/p>\n Study senior author Jishen Qiu, an associate professor in civil engineering, said: \u201cMy inspiration came from freeze-dried fruits that become harder.<\/p>\n Living building material can be 3D printed under simulated Martian conditions at 30\u00b0C and 0.01 atm. (Ning Liu via SWNS)<\/p>\n By Talker<\/p>\n \u201cMars\u2019s extremely low temperature and pressure create conditions similar to freeze-drying.<\/p>\n \u201cSo I asked myself if we can take advantage of that and make some materials.\u201d<\/p>\n To conjure the printable material, Qiu needed the right mixture of sand and glue, the latter, which is made from gelatin and a specialized yeast<\/a>.<\/p>\n His team at The Hong Kong University of Science and Technology<\/a> engineered yeast coated with highly adhesive proteins, including those that mussels use to cling to rocks.<\/p>\n Qiu explained that the gelatin knits the ingredients together and provides a place for the cells to grow, while the sand gives mass and structure.<\/p>\n The team then tested the material in simulated Martian conditions.<\/p>\n Once the mixture pushes through the nozzle, the extreme cold and low pressure freeze-dry it.<\/p>\n Water freezes and turns directly from ice into vapor, leaving behind microscopic pores.<\/p>\n Qiu says the result resembles a foam, light and porous.<\/p>\n For now, the printed structures are about wine-cork-sized small domes, standing at 45 millimeters (1.7 inches) tall and 30 millimeters (1.18 inches) wide.<\/p>\n But the material itself is strong with a compressive strength of 10 to 12 megapascals \u2014 comparable to low-grade concrete, according to the research published in the journal Chem Circularity<\/a>.<\/p>\n Qiu said: \u201cThis is actually strong enough to build a one- or two-story building on Earth whose gravity is three times that of Mars.<\/p>\n \u201cSo, you can probably easily build a multistory building on Mars with the material.\u201d<\/p>\n Many proposals for building extraterrestrial cities<\/a> involve heating and melting Martian rocks or moon dust into bricks and beams.<\/p>\n But that requires substantial energy.<\/p>\n Qiu says the biology-based material not only saves energy on heat by taking an entirely different manufacturing approach, but it could also support a circular economy<\/a> on Mars.<\/p>\n He explained that settlers could recover the yeast from dismantled structures and regrow it in bioreactors.<\/p>\n Qiu said: \u201cAs long as there\u2019s one yeast that\u2019s still alive, you can grow them again.\u00a3<\/p>\n A microscopic view reveals the materials porous structure with polymers and engineered yeast highlighted in yellow. (Ning Liu via SWNS)<\/p>\n By Talker<\/p>\n So far, the biology-based material has only been tested on Earth.<\/p>\n The Hong Kong team doesn\u2019t know whether the yeasts can survive actual Martian conditions.<\/p>\n<\/p>\n
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